Using 4 tubes, this 1924 receiver combines new technologies as an intermediate frequency stage that was already beginning to appear. Listening is via phone and battery power.
We found this 4W transmitter in a Mullard transistor manual from 1960. The circuit is powered by...
This circuit was found in a 1977 Radio Handbook. The MOSFET supports an equivalent. Capacitor C must...
This simple alarm was found in a 1982 documentation, but uses components that are still common,...